Preparing competent JM109

[BOIS, DANUTA H]

Hi, 
I've been trying to prepare competent E. coli JM 109 and the best I can
do is 10E5 cfu/ug.  I've tried the Inoue method (Gene 96:23-28, 1990), 
which worked so well for DH5alpha (over 5x10E7 cfu/ug) and the one-step
TSS method in the red book.  I'm wondering whether JM109 is difficult
to make competent, whether I'm doing something wrong, or whether I have 
the wrong protocol for these bacteria. Does anyone have any suggestions?

Sincerely, 

Danuta Bois